Make ice and magma beams more resistible (25%, 35%).

git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@6847 c06c8d41-db1a-0410-9941-cceddc491573

Created by  dshaligram  on August 22, 2008
J6UUHGYPNXKKWVMIWS5DNPGQBBCGBMABSSWVZZWO3MXICF5GAUWAC
Change contents